Nematic liquid crystal composition

ABSTRACT

A liquid crystal composition exhibits a positive dielectric anisotropy and sufficiently low viscosity without decreasing or increasing refractive index anisotropy or nematic phase-isotropic liquid phase transition temperature, and does not cause display failures. The liquid crystal composition contains one or more compounds selected from compounds represented by general formula (LC0) and one or more compounds selected from a group of compounds represented by general formula (LC1) to general formula (LC5), in which the liquid crystal composition contains one or more compounds in which at least one of A 01 , A 02 , and A 11  to A 42  in general formulae (LC0) to (LC4) represents a tetrahydropyran-2,5-diyl group.

TECHNICAL FIELD

The present invention relates to a nematic liquid crystal compositionuseful as an electro-optic liquid crystal display material and havingpositive dielectric anisotropy (Δ∈).

BACKGROUND ART

Liquid crystal display devices are being used in watches, calculators,various measurement instruments, automobile panels, word processors,electronic organizers, printers, computers, televisions, clocks,advertising boards, etc. Typical examples of the liquid crystal displaymode include TN (twisted nematic) mode, STN (super twisted nematic)mode, a VA mode featuring vertical alignment using TFTs (thin filmtransistors), and an IPS (in-plane switching) mode/FFS mode featuringhorizontal alignment. Liquid crystal compositions used in these liquidcrystal display devices are required to be stable against externalfactors such as moisture, air, heat, and light, stay in a liquid crystalphase in a temperature range as wide as possible centered around roomtemperature, exhibit low viscosity, and operate at a low drive voltage.A liquid crystal composition is composed of several to dozens ofcompounds in order to optimize the dielectric anisotropy (Δ∈),refractive index anisotropy (Δn), and/or other properties for individualdisplay devices.

A vertical alignment-mode display uses a liquid crystal compositionhaving a negative Δ∈. A horizontal alignment-mode display such as a TN,STN, or IPS-mode display uses a liquid crystal composition having apositive Δ∈. In recent years, a drive mode with which a liquid crystalcomposition having a positive Δ∈ is vertically aligned under absence ofapplied voltage and an image is displayed by applying an IPS/FFS-modeelectric field has been reported and the necessity for a liquid crystalcomposition having a positive Δ∈ is increasing. Meanwhile, low-voltagedriving, high-speed response, and wide operation temperature range arerequired in all driving modes. In other words, Δ∈ that is positive andhas a large absolute value, a low viscosity (η), and a high nematicphase-isotropic liquid phase transition temperature (T_(ni)) aredesirable. Moreover, due to the setting of Δn×d, which is the product ofΔn and a cell gap (d), it is necessary to adjust the Δn of the liquidcrystal composition to be within an appropriate range according to thecell gap. In addition, since high-speed response is important inapplying a liquid crystal display device to a television or the like, aliquid crystal composition with a small γ₁ is required.

Liquid crystal compositions that use a compound having a positive Δ∈ andrepresented by formula (A-1) or (A-2) as a constitutional component of aliquid crystal composition have been disclosed (PTL 1 to PTL 4).However, these liquid crystal compositions do not achieve sufficientlylow viscosity.

CITATION LIST Patent Literature

PTL 1: WO96/032365

PTL 2: Japanese Unexamined Patent Application Publication No. 09-157202

PTL 3: WO98/023564

PTL 4: Japanese Unexamined Patent Application Publication No.2003-183656

SUMMARY OF INVENTION Technical Problem

An object of the present invention is to provide a liquid crystalcomposition that has refractive index anisotropy (Δn) adjusted to adesired level and a positive dielectric anisotropy (Δ∈) and exhibitssufficiently low viscosity (η) without degrading the nematic phasetemperature range by suppressing the decrease in the nematicphase-isotropic liquid phase transition temperature (T_(ni)) and theincrease in lower limit temperature of the nematic phase.

Solution to Problem

The inventors of the present invention have studied variousfluorobenzene derivatives and found that the object can be achieved bycombining specific compounds. Thus, the present invention has been made.

The present invention provides a liquid crystal composition having apositive dielectric anisotropy and containing one or more compoundsselected from compounds represented by general formula (LC0) and one ormore compounds selected from a group of compounds represented by generalformula (LC1) to general formula (LC5), wherein the liquid crystalcomposition contains one or more compounds in which at least one of A⁰¹,A⁰², and A¹¹ to A⁴² in general formulae (LC0) to (LC4) represents atetrahydropyran-2,5-diyl group:

(In the formulae, R⁰¹ to R⁴¹ each independently represent an alkyl grouphaving 1 to 15 carbon atoms where one or more —CH₂— in the alkyl groupmay each be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C≡C—,—CF₂O—, or —OCF₂— so long as oxygen atoms are not directly adjacent toeach other and one or more hydrogen atoms in the alkyl group may each besubstituted with a halogen; R⁵¹ and R⁵² each independently represent analkyl group having 1 to 15 carbon atoms where one or more —CH₂— in thealkyl group may each be substituted with —O—, —CH═CH—, —CO—, —OCO—,—COO—, or —C≡C— so long as oxygen atoms are not directly adjacent toeach other, and may each represent —OCF₃ or —CF₃— when A⁵¹ or A⁵³described below represents a cyclohexane ring; A⁰¹ to A⁴² eachindependently represent any one of structures below:

(In the structures, one or more —CH₂— in the cyclohexane ring may eachbe substituted with —O— so long as oxygen atoms are not directlyadjacent to each other; in the structures, one or more —CH═ in thebenzene ring may each be substituted with —N═ so long as nitrogen atomsare not directly adjacent to each other; and X⁶¹ and X⁶² eachindependently represent —H, —Cl, —F, —CF₃, or —OCF₃); A⁵¹ to A⁵³ eachindependently represent any one of structures below:

(In the formulae, one or more —CH₂CH₂— in the cyclohexane ring may eachbe substituted with —CH═CH—, —CF₂O—, or —OCF₂— and one or more —CH═ inthe benzene ring may each be substituted with —N═ so long as nitrogenatoms are not directly adjacent to each other); X⁰¹ represents ahydrogen atom or a fluorine atom; X¹¹ to X⁴³ each independentlyrepresent —H, —Cl, —F, —CF₃, or —OCF₃; Y each Y⁰¹ to Y⁴¹ represent —Cl,—F, —OCHF₂, —CF₃, or —OCF₂; Z⁰¹ and Z⁰² each independently represent asingle bond, —CH═CH—, —C≡C—, —CH₂CH₂—, —(CH₂)₄—, —OCF₂—, or —CF₂O—; Z³¹to Z⁴² each independently represent a single bond, —CH═CH—, —C≡C—,—CH₂CH₂—, —(CH₂)₄—, —OCF₂—, or —CF₂O— where at least one of Z³¹ and Z³²that are present represents a group other than a single bond; Z⁵¹ andZ⁵² each independently represent a single bond, —CH═CH—, —C≡C—,—CH₂CH₂—, —(CH₂)₄—, —OCH₂—, —CH₂O—, —OCF₂— or —CF₂O—; m⁰¹ to m⁵¹ eachindependently represent an integer of 0 to 3; m⁰¹+m⁰², m³¹+m³², andm⁴¹+m⁴² are each independently 1, 2, 3, or 4; and when a plurality ofA⁰¹, A⁰³, A²³, A³¹, A³², A⁴¹, A⁴², A⁵², Z⁰¹, Z⁰², Z³¹, Z³², Z⁴¹, Z⁴²,and/or Z⁵² are present, they may be the same or different).

Advantageous Effects of Invention

The liquid crystal composition according to the present inventionfeatures a positive Δ∈ having a large absolute value. Moreover, η islow, the rotational viscosity (γ₁) is small, the liquid crystalproperties are excellent, and a stable liquid crystal phase is achievedover a wide temperature range. Moreover, the liquid crystal compositionis chemically stable against heat, light, water, etc., can be driven ata low voltage, is practical, and has high reliability.

DESCRIPTION OF EMBODIMENTS

A liquid crystal composition according to the invention of the presentapplication contains one or more compounds selected from compoundsrepresented by general formula (LC0) above and one or more compoundsselected from a compound group consisting of compounds represented bygeneral formulae (LC1) to (LC5). Since a liquid crystal compositioncontaining compounds represented by general formula (LC0) and compoundsrepresented by general formulae (LC1) to (LC5) exhibits a stable liquidcrystal phase even at low temperature, the liquid crystal compositioncan be regarded as a practical liquid crystal composition.

In general formulae (LC0) to (LC5), R⁰¹ to R⁵² preferably eachindependently represent an alkyl group having 1 to 8 carbon atoms, analkenyl group having 2 to 8 carbon atoms, or an alkoxy group having 1 to8 carbon atoms and are preferably linear. When R⁰¹ to R⁵² are torepresent alkenyl groups, selection is preferably made from groupsrepresented by formulae (R1) to (R5):

(In each formula, the black dot represents a bonding point to a ring.)

In the case where A⁰¹, A⁰¹, A²¹, A³¹, A⁴¹, A⁵¹, and A⁵³ each represent atrans-1,4-cyclohexylene group, groups represented by formulae (R1),(R2), and (R4) are more preferable. It is yet more preferable to containone or more compounds represented by general formula (LC5) in which atleast one selected from R⁵¹ and R⁵³ represents an alkenyl grouprepresented by a formula selected from formulae (R1) to (R5). A⁰¹ to A⁴²preferably each independently represent a trans-1,4-cyclohexylene group,a 1,4-phenylene group, a 3-fluoro-1,4-phenylene group, a3,5-difluoro-1,4-phenylene group, or a tetrahydropyran-2,5-diyl group.In the case where some of A⁰¹ to A⁴² are to represent atetrahydropyran-2,5-diyl group, A⁰¹, A¹¹, A²¹, A³¹, and A⁴¹ preferablyrepresent this group. Examples of preferable compounds containing atetrahydropyran-2,5-diyl group include compounds represented by generalformula (LC0-7) to general formula (LC0-9), general formula (LC0-23),general formula (LC0-24), general formula (LC0-26), general formula(LC0-27), general formula (LC0-20), general formula (LC0-40), generalformula (LC0-51) to general formula (LC0-53), general formula (LC0-110),general formula (LC0-111), general formula (LC2-9) to general formula(LC2-14), general formula (LC3-23) to general formula (LC3-32), generalformula (LC4-12) to general formula (LC4-14), general formula (LC4-16),general formula (LC4-19), and general formula (LC4-22). In such a case,at least one compound selected from this compound group is morepreferably contained in order to achieve the object of the presentinvention.

A⁵¹ to A⁵³ preferably each independently represent atrans-1,4-cyclohexylene group, a 1,4-phenylene group, a3-fluoro-1,4-phenylene group, or a 2-fluoro-1,4-phenylene group.

Z⁰¹ and Z⁰² preferably each independently represent a single bond,—CH═CH—, —C≡C—, —CH₂CH₂—, —OCF₂—, or —CF₂O—. In the case where one ofZ⁰¹ and Z⁰² that are present represents —CH═CH—, —C≡C—, —CH₂CH₂—,—(CH₂)₄—, —OCF₂—, or —CF₂O—, the other preferably represents a singlebond. Z⁰¹ and Z⁰² preferably both represent a single bond.

Z³¹ to Z⁴² preferably each independently represent a single bond,—CH═CH—, —C≡C—, —CH₂CH₂—, —OCH₂—, —CH₂O—, —OCF₂—, or —CF₂O—. In the casewhere one of Z³¹ to Z⁴² that are present represents —CH═CH—, —C≡C—,—CH₂CH₂—, —(CH₂)₄—, —OCF₂—, or —CF₂O—, the others preferably eachrepresent a single bond.

Z⁵¹ and Z⁵² preferably each independently represent a single bond,—CH═CH—, —C≡C—, —CH₂CH₂—, —OCF₂—, or —CF₂O—. In the case where one ofZ⁵¹ and Z⁵² that are present represents —CH═CH—, —C≡C—, —CH₂CH₂—,—(CH₂)₄—, —OCH₂—, —CH₂O—, —OCF₂—, or —CF₂O—, the other preferablyrepresents a single bond. More preferably, Z⁵¹ and Z⁵² both represent asingle bond.

X⁰¹ in general formula (LC0) is preferably F since a significantly lowviscosity (η) is achieved relative to a high dielectric anisotropy (Δ∈)or the same level of dielectric anisotropy (Δ∈). X¹¹ to X⁴³ preferablyeach independently represent H or F, and X¹¹, X²¹, X³¹, and X⁴¹preferably each represent F.

Y⁰¹ to Y⁴¹ particularly preferably each independently represent F, CF₃,or OCF₃. While m⁰¹ to m⁵¹ may each independently represent an integer of0 to 23, m⁰¹+m⁰² is particularly preferably 1 or 2, m²¹ is particularlypreferably 0, m³¹+m³² is particularly preferably 1, 2, or 3, and m⁴¹+m⁴²is particularly preferably 1 or 2.

The liquid crystal compound represented by general formula (LC0) ispreferably a compound represented by any one of general formula (LC0-a)to (LC0-h) (in the formulae, R⁰¹, A⁰¹, A⁰², A⁰³, Z⁰¹, Z⁰², X⁰¹, and Y⁰¹are the same as those in general formula (LC0) and when two or more A⁰¹and A⁰³, and/or Z⁰¹ and Z⁰² are present, they may be the same ordifferent).

More preferable are the compounds represented by general formula (LC0-1)to general formula (LC0-111) below:

(In the formulae, R is the same as R⁰¹ in general formula (LC0), “—F,CF₃, OCF₃” denotes that Y⁰¹ each independently represent one of —F, CF₃,and OCF₃, and “(—F)” denotes H or F serving as a substituent.) Compoundsrepresented by general formula (LC0-1) to general formula (LC0-19) areparticularly preferable since they have high dielectric anisotropy (Δ∈),notably low viscosity (η), and good compatibility. Compounds representedby general formulae (LC0-20) to general formula (LC0-111) areparticularly preferable since they have high dielectric anisotropy (Δ∈),relatively low viscosity (11), and a high nematic phase-isotropic liquidphase transition temperature (T_(ni)).

The compounds represented by general formula (LC2) are more preferablycompounds represented by general formula (LC2-1) to general formula(LC2-14) below:

(In the formulae, X²³, X²⁴, X²⁵, and X²⁶ each independently represent ahydrogen atom, Cl, F, CF₃, or OCF₃, and X²², R²¹, and Y²¹ are the sameas those in general formula (LC2)). The group of compounds representedby general formula (LC2-1) to general formula (LC2-4) and generalformula (LC2-9) to general formula (LC2-11) is more preferable.

The compounds represented by general formula (LC3) are more preferablycompounds represented by general formula (LC3-1) to general formula(LC3-32) below:

(In the formulae, X³³, X³⁴, X³⁵, X³⁶, X³⁷, and X³⁸ each independentlyrepresent H, Cl, F, CF₃, or OCF₃, and X³², R³¹, A³¹, Y³¹, and Z³¹ arethe same as those in general formula (LC3).) Among these, the group ofthe compounds represented by general formula (LC3-5), general formula(LC3-15), and general formula (LC3-20) to general formula (LC3-32) ismore preferably used in combination with the essential component of thepresent invention represented by general formula (LC0). More preferably,a compound selected from the group of compounds represented by generalformula (LC3-20) and general formula (LC3-21) with X³³ and X³⁴ eachrepresenting F and/or the group of tetrahydropyran-ring-containingcompounds represented by general formula (LC3-25), general formula(LC3-26), and general formula (LC3-30) to general formula (LC3-32) arepreferably used in combination with the essential component of thepresent invention represented by general formula (LC0).

The compounds represented by general formula (LC4) are more preferablycompounds represented by general formula (LC4-1) to general formula(LC4-23) below:

(In the formulae, X⁴⁴, X⁴⁵, X⁴⁶, and X⁴⁷ each independently represent H,Cl, F, CF₃, or OCF₃, and X⁴², X⁴³, R⁴¹, and Y⁴¹ are the same as those ingeneral formula (LC4).) Among these, the group of compounds representedby general formula (LC4-1) to general formula (LC4-3), general formula(LC4-6), general formula (LC4-9), general formula (LC4-10), and generalformula (LC4-12) to general formula (LC4-17) are more preferably used incombination with the essential component of the present inventionrepresented by general formula (LC0). Furthermore, among these, acompound selected from the group of compounds represented by generalformula (LC4-9) to general formula (LC4-11) and general formula (LC4-15)to general formula (LC4-17) with X⁴⁴ and/or X⁴⁵ representing F is morepreferably used in combination with the essential component of thepresent invention represented by general formula (LC0).

The compounds represented by general formula (LC5) are more preferablycompounds represented by general formula (LC5-1) to general formula(LC5-26) below:

(In the formulae, R⁵¹ and R⁵² are the same as those in general formula(LC5).) Among these, the group of compounds represented by generalformula (LC5-1) to general formula (LC5-8), general formula (LC5-14),general formula (LC5-16), and general formula (LC5-18) to generalformula (LC5-26) is particularly preferably used in combination with theessential component of the present invention represented by generalformula (LC0). At least one of R⁵¹ and R⁵² in general formula (LC5-1)and general formula (LC5-4) preferably represents an alkenyl group andmore preferably an alkenyl group selected from those represented byformulae (R1) to (R5) below.

One or more compounds represented by general formula (LC5) arepreferably contained. The content thereof is preferably 20 to 70% bymass and more preferably 30 to 70% by mass.

The liquid crystal composition of the present invention contains acompound represented by general formula (LC0) and a compound selectedfrom the group of compounds represented by general formula (LC1) togeneral formula (LC5). Of these compounds, at least one compound is acompound having a tetrahydropyran-2,5-diyl group and the content thereofis preferably in the range of 5 to 50% by mass and more preferably inthe range of 10 to 40% by mass. The compound having atetrahydropyran-2,5-diyl group which is an essential component of theliquid crystal composition of the present invention is preferably acompound represented by general formula (LC0), at least one of A⁰¹ andA⁰² in general formula (LC0) preferably represents atetrahydropyran-2,5-diyl group, and the content thereof is preferably 5to 50% by mass.

The liquid crystal composition of the present invention preferably has aviscosity η of 20 mPa·s or less at 20° C.

The liquid crystal composition of the present invention may contain oneor more optically active compounds. The optically active compounds maybe any capable of twisting and aligning liquid crystal molecules. Sincetwisting normally changes depending on temperature, plural opticallyactive compounds may be used to obtain a desired temperature dependence.In order not to adversely affect the nematic liquid crystal phasetemperature range, viscosity, and the like, it is preferable to selectand use optically active compounds that have a powerful twisting effect.Examples of such optically active compounds to be contained includeliquid crystals such as cholesteric nonanoate and compounds representedby general formula (Ch-1) to general formula (Ch-6) below:

(In the formulae, R_(c1), R_(c2), and R* each independently represent analkyl group having 1 to 15 carbon atoms where one or more —CH₂— in thealkyl group may each be substituted with —O—, —CH═CH—, —CO—, —OCO—,—COO—, —C≡C—, —CF₂O—, or —OCF₂— so long as oxygen atoms are not directlyadjacent to each other and one or more hydrogen atoms in the alkyl groupmay each be substituted with a halogen; R* includes at least oneoptically active branched chain group or halogen substituent; Z_(c1) andZ_(c2) each independently represent a single bond, —CH═CH—, —C≡C—,—CH₂CH₂—, —(CH₂)₄—, —COO—, —OCO—, —OCH₂—, —CH₂O—, —OCF₂—, or —CF₂O—; D₁and D₂ each represent a cyclohexane ring or a benzene ring where one ormore —CH₂— in the cyclohexane ring may each be substituted with —O— solong as oxygen atoms are not directly adjacent to each other, one ormore —CH₂CH₂— in the ring may each be substituted with —CH═CH—, —CF₂O—,or —OCF₂—, one or more —CH═ in the benzene ring may each be substitutedwith —N═ so long as nitrogen atoms are not directly adjacent to eachother, and one or more hydrogen atoms in the ring may each besubstituted with F, Cl, or CH₃; t₁ and t₂ each represent 0, 1, 2, or 3;and MG*, Q_(c1), and Q_(c2) each represent the structure below:

(In the formula, D₃ and D₄ each represent a cyclohexane ring or abenzene ring, one or more —CH₂— in the cyclohexane ring may each besubstituted with —O— so long as oxygen atoms are not directly adjacentto each other, one or more —CH₂CH₂— in the ring may each be substitutedwith —CH═CH—, —CF₂O—, or —OCF₂—, one or more —CH═ in the benzene ringmay each be substituted with —N═ so long as nitrogen atoms are notdirectly adjacent to each other, and one or more hydrogen atoms in thering may each be substituted with F, Cl, or CH₃.)

The liquid crystal composition of the present invention may contain oneor more polymerizable compounds. The polymerizable compounds arepreferably discotic liquid crystal compounds which have a benzenederivative, a triphenylene derivative, a truxene derivative, aphthalocyanine derivative, or a cyclohexane derivative as a core at themolecular center and linear alkyl groups, linear alkoxy groups, orsubstituted benzoyloxy groups as side chains radially substituting thecore.

To be specific, the polymerizable compounds are preferably compoundsrepresented by general formula (PC):

(In the formula, P₁ represents a polymerizable functional group, Sp₁represents a spacer group having 0 to 20 carbon atoms, Q_(p1) representsa single bond, —O—, —NH—, —NHCOO—, —OCONH—, —CH═CH—, —CO—, —COO—, —OCO—,—OCOO—, —OOCO—, —CH═CH—, —CH═CH—COO—, —OCO—CH═CH—, or —C≡C—, p₁ and p₂each independently represent 1, 2, or 3, MG_(p) represents a mesogenicgroup or a mesogenic supporting group, and R_(p1) represents a halogenatom, a cyano group, or an alkyl group having 1 to 25 carbon atoms whereone or more CH₂ group in the alkyl group may each be substituted with—O—, —S—, —NH—, —N(CH₃)—, —CO—, —COO—, —OCO—, —OCOO—, —SCO—, —COS—, or—C≡C— so long as oxygen atoms are not directly adjacent to each other,or R_(p1) may represent P₂-Sp₂-Q_(p2)- where P₂, Sp₂, and Q_(p2) arerespectively the same as P₁, Sp₁, and Q_(p1).)

More preferably, the polymerizable compounds are those represented bygeneral formula (PC) with MG_(p) representing the following structure:

(In the formula, C₀₁ to C₀₃ each independently represent a 1,4-phenylenegroup, a 1,4-cyclohexylene group, a 1,4-cyclohexenyl group, atetrahydropyran-2,5-diyl group, a 1,3-dioxane-2,5-diyl group, atetrahydrothiopyran-2,5-diyl group, a 1,4-bicyclo(2,2,2)octylene group,a decahydronaphthalene-2,6-diyl group, a pyridine-2,5-diyl group, apyrimidine-2,5-diyl group, a pyradine-2,5-diyl group, a1,2,3,4-tetrahydronaphthalene-2,6-diyl group, a 2,6-naphthylene group, aphenanthrene-2,7-diyl group, a 9,10-dihydrophenanthrene-2,7-diyl group,a 1,2,3,4,4a,9,10a-octahydrophenanthrene-2,7-diyl group, or afluorene-2,7-diyl group; the 1,4-phenylene group, the1,2,3,4-tetrahydronaphthalene-2,6-diyl group, the 2,6-naphthylene group,the phenanthrene-2,7-diyl group, the 9,10-dihydrophenanthrene-2,7-diylgroup, the 1,2,3,4,4a,9,10a-octahydrophenanthrene-2,7-diyl group, andthe fluorene-2,7-diyl group may each have, as a substituent, one or moreselected from F, Cl, CF₃, OCF₃, a cyano group, an alkyl group having 1to 8 carbon atoms, an alkoxy group, an alkanoyl group, an alkanoyloxygroup, an alkenyl group having 2 to 8 carbon atoms, an alkenyloxy group,an alkenoyl group, and an alkenoyloxy group; Z_(p1) and Z_(p2) eachindependently represent —COO—, —OCO—, —CH₂CH₂—, —OCH₂—, —CH₂O—, —CH═CH—,—C≡C—, —CH═CHCOO—, —OCOCH═CH—, —CH₂CH₂COO—, —CH₂CH₂OCO—, —COOCH₂CH₂—,—OCOCH₂CH₂—, —CONH—, —NHCO—, or a single bond; and p₃ represents 0, 1,or 2.)

In the case where Sp₁ and Sp₂ each independently represent an alkylenegroup, the alkylene group may be substituted with one or more halogenatoms or CN and one or more CH₂ groups present in this group may each besubstituted with —O—, —S—, —NH—, —N(CH₂)—, —CO—, —COO—, —OCO—, —OCOO—,—SCO—, —COS—, or —C≡C— so long as oxygen atoms are not directly adjacentto each other. P₁ and P₂ preferably each independently represent a groupselected from those represented by general formulae below:

(In the formulae, R_(p2) to R_(p6) each independently represent ahydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbonatoms.)

To be more specific, the polymerizable compounds represented by generalformula (PC) are preferably compounds represented by general formula(PC0-1) to general formula (PC0-6) below:

[Chem. 23]

(P₁-Sp₁-Q_(p1)_(p) ₁ MG_(p)Q_(p2)-Sp₂-P₂)_(p) ₄   (PC0-1)

(P₁-Q_(p1)_(p) ₁ MG_(p)Q_(p2)-P₂)_(p) ₄   (PC0-2)

P₁-Sp₁-Q_(p1)-MG_(p)-Q_(p2)-Sp₂-P₂  (PC0-3)

P₁-Q_(p1)-MG_(p)-Q_(p2)-P₂  (PC0-4)

P₁-Sp₁-Q_(p1)-MG_(p)-R_(p1)  (PC0-5)

P₁-Q_(p1)-MG_(p)-R_(p1)  (PC0-6)

(In the formulae, p₄ each independently represent 1, 2, or 3.) Thepolymerizable compounds represented by general formula (PC0) are morepreferably compounds represented by more specific formulae, namely,general formula (PC1-1) to general formula (PC1-9) below:

(In the formulae, p₅ represents 0, 1, 2, 3, or 4.)

More preferable are polymerizable compounds represented by generalformula (PC) to general formula (PC1-9) with Sp₁, Sp₂, Q_(p1), andQ_(p2) all representing single bonds, polymerizable compounds with P₁and P₂ representing a group represented by formula (PC0-a), an acrylate,and/or a methacrylate, polymerizable compounds represented by generalformula (PC0-1) and general formula (PC0-2) with p₁ and p₄ satisfyingp₁+p₄=1 to 6, and polymerizable compounds represented by general formula(PC1-1) and general formula (PC1-9) with R_(p1) representing F, CF₃,OCF₃, CH₃, or OCH₃, where the number of substituents R_(p1) is 1, 2, 3,or 4.

Also preferable is a discotic liquid crystal compound represented bygeneral formula (PC) with MG_(p) representing a group represented bygeneral formula (PC1)-9.

(In the formulae, R₇ each independently represent P₁-Sp₁-Q_(p1) or asubstituent represented by general formula (PC1-e), R₈₁ and R₈₂ eachindependently represent a hydrogen atom, a halogen atom, or a methylgroup, R₈₃ represents an alkoxy group having 1 to 20 carbon atoms, andat least one of hydrogen atoms in the alkoxy group is substituted with asubstituent represented by any one of general formulae (PC0-a) to(PC0-d) above.) The amount of the polymerizable compounds used ispreferably 0.05 to 2.0% by mass.

The liquid crystal composition of the present invention containing apolymerizable compound is used to manufacture a liquid crystalcomposition through polymerizing the polymerizable compound. During thisprocess, the amount of the unpolymerized components is preferablydecreased to a desired level or less. A liquid crystal composition ofthe present invention suited for this use preferably contains a compoundhaving a biphenyl group or a terphenyl group as a partial structure ingeneral formula (LC0). More specifically, it is preferable to use 0.1 to40% by mass of at least one selected from the group of compoundsrepresented by general formula (LC0-4) to general formula (LC0-6),general formula (LC0-10) to general formula (LC0-16), and generalformula (LC0-27) to general formula (LC0-107). The compound ispreferably used in combination with a polymerizable compound selectedfrom those represented by general formula (PL1-1) to general formula(PL1-3), general formula (PC1-8), and general formula (PC1-9).

The liquid crystal composition may further contain one or moreantioxidants and one or more UV absorbers. The antioxidant is preferablyselected from those represented by general formula (E-1) and/or generalformula (E-2) below:

(In the formulae, R_(e1) represents an alkyl group having 1 to 15 carbonatoms, one or more —CH₂— in the alkyl group may each be substituted with—O—, —CH═CH—, —CO—, —OCO—, —COO—, —C≡C—, —CF₂O—, or —OCF₂— so long asoxygen atoms are not directly adjacent to each other, and one or morehydrogen atoms in the alkyl group may each be substituted with ahalogen;Z_(e1) and Z_(e2) each independently represent a single bond, —CH═CH—,—C≡C—, —CH₂CH₂—, —(CH₂)₄—, —COO—, —OCO—, —OCH₂—, —CH₂O—, —OCF₂—, or—CF₂O—; andE₁ represents a cyclohexane ring or a benzene ring, one or more —CH₂— inthe cyclohexane ring may each be substituted with —O— so long as oxygenatoms are not directly adjacent to each other, one or more —CH₂CH₂— inthe ring may each be substituted with —CH═CH—, —CF₂O—, or —OCF₂—, one ormore —CH═ in the benzene ring may each be substituted with —N═ so longas nitrogen atoms are not directly adjacent to each other, one or morehydrogen atoms in the ring may each be substituted with F, Cl, or CH₃,and q₁ represents 0, 1, 2, or 3.)

The liquid crystal composition according to the present invention can beused in liquid crystal display devices, in particular, active matrixdriving liquid crystal display devices of, for example, TN mode, OCBmode, ECB mode, IPS (including FFS electrodes) mode, or VA-IPS mode(including FFS electrodes). Here, the VA-IPS mode refers to a drivingmode in which a liquid crystal material having a positive dielectricanisotropy (Δ∈>0) is vertically aligned with respect to the substratesurface in the absence of applied voltage and liquid crystal moleculesare driven by using pixel electrodes and a common electrode arranged onthe same substrate surface. Since liquid crystal molecules align in adirection of the curved electric field generated by the pixel electrodesand the common electrode, it is easy to divide pixels into sub-areas toform a multi-domain structure and enhance response. Such a system isreferred to as EOC, VA-IPS, etc., according to Non-Patent LiteraturesProc. 13th IDW, 97 (1997), Proc. 13th IDW, 175 (1997), SID Sym. Digest,319 (1998), SID Sym. Digest, 838 (1998), SID Sym. Digest, 1085 (1998),SID Sym. Digest, 334 (2000), and Eurodisplay Proc., 142 (2009). In thepresent invention, the name “VA-IPS” is used.

In general, the threshold voltage (Vc) of the Freedericksz transitionfor TN and ECB mode is determined by the following expression:

$\begin{matrix}{{Vc} = {\frac{\pi \; d_{cell}}{d_{cell} + {\langle r_{1}\rangle}}\sqrt{\frac{K\; 11}{\Delta ɛ}}}} & \left\lbrack {{Math}.\mspace{14mu} 1} \right\rbrack\end{matrix}$

Vc for STN mode is determined by the following expression:

$\begin{matrix}{{Vc} = {\frac{\pi \; d_{gap}}{d_{cell} + {\langle r_{2}\rangle}}\sqrt{\frac{K\; 22}{\Delta ɛ}}}} & \left\lbrack {{Math}.\mspace{14mu} 2} \right\rbrack\end{matrix}$

Vc for VA mode is determined by the following expression:

$\begin{matrix}{{Vc} = {\frac{\pi \; d_{cell}}{d_{cell} - {\langle r_{3}\rangle}}\sqrt{\frac{K\; 33}{{\Delta ɛ}}}}} & \left\lbrack {{Math}.\mspace{14mu} 3} \right\rbrack\end{matrix}$

(In the expressions, Vc denotes the Freedericksz transition (V), πdenotes the circular constant, d_(cell) denotes the gap (μm) between afirst substrate and a second substrate, d_(gap) denotes the gap (μm)between the pixel electrodes and the common electrode, d_(ITO) denotesthe width (μm) of the pixel electrodes and/or the common electrode,<r1>, <r2>, and <r3> denote the extrapolation length (μm), K11 denotesthe splay elastic constant (N), K22 denotes the twist elastic constant(N), K33 denotes the bend elastic constant (N), and Δ∈ denotes thedielectric anisotropy.)

It has been found that the following mathematical expression 4 isapplicable to the present invention etc., for VA-IPS mode:

$\begin{matrix}{{Vc} \propto {\frac{d_{gap} - {\langle r^{\prime}\rangle}}{d_{ITO} + {\langle r\rangle}}\frac{\pi \; d_{cell}}{d_{cell} - {\langle r_{3}\rangle}}\sqrt{\frac{K\; 33}{{\Delta ɛ}}}}} & \left\lbrack {{Math}.\mspace{14mu} 4} \right\rbrack\end{matrix}$

(In the expression, Vc denotes the Freedericksz transition (V), ndenotes the circular constant, d_(cell) denotes the gap (μm) between afirst substrate and a second substrate, d_(gap) denotes the gap (μm)between the pixel electrodes and the common electrode, d_(ITO) denotesthe width (μm) of the pixel electrodes and/or the common electrode, <r>,<r′>, and <r3> denote the extrapolation length (μm), K33 denotes thebend elastic constant (N), and Δ∈ denotes the dielectric anisotropy.)Mathematical expression 4 shows that the cell structure may be designedto decrease d_(gap) as much as possible and increase d_(ITO) as much aspossible to achieve low drive voltage and that a liquid crystalcomposition having Δ∈ with a large absolute value and a low K33 may beselected as the liquid crystal composition to achieve low drive voltage.

The liquid crystal composition of the present invention can be adjustedto exhibit desirable Δ∈, K11, K33, etc.

The product (Δn·d) of the refractive index anisotropy (Δn) of the liquidcrystal composition and the gap (d) between the first substrate and thesecond substrate of a display device is strongly related to viewingangle characteristics and response speed. Accordingly, the gap (d) tendsto be as small as 3 to 4 μm. The product (Δn·d) is particularlypreferably 0.31 to 0.33 for the TN, ECB, and IPS (liquid crystal alignssubstantially horizontal to the substrate surface in the absence ofapplied voltage) modes. For the VA-IPS mode, the product is preferably0.20 to 0.59 and more preferably 0.30 to 0.40 if the alignment isvertical with respect to the two substrates. Since the suitable value ofthe product (Δn·d) differs depending on the mode of the display device,a liquid crystal composition capable of exhibiting a refractive indexanisotropy (Δn) in various different ranges, such as 0.070 to 0.110,0.100 to 0.140, or 0.130 to 0.180 is required. In order to obtain asmall or relatively small refractive index anisotropy (Δn) from theliquid crystal composition of the present invention, it is preferable touse 0.1 to 80% by mass of one or more compounds selected from the groupconsisting of compounds represented by general formula (LC0-1) togeneral formula (LC0-3), general formula (LC0-7) to general formula(LC0-9), and general formula (LC0-20) to general formula (LC0-30). Inorder to obtain a large or relatively large refractive index anisotropy(Δn), it is preferable to use 0.1 to 60% by mass of one or morecompounds selected from the group consisting of compounds represented bygeneral formula (LC0-4) to general formula (LC0-6), general formula(LC0-10) to general formula (LC0-16), and general formula (LC0-27) togeneral formula (LC0-107). For the TN and ECB modes that require theliquid crystal to align substantially horizontal to the substratesurface in the absence of applied voltage, the tilt angle is preferably0.5 to 7°. For the VA-IP mode that requires the liquid crystal to alignsubstantially perpendicular to the substrate surface in the absence ofapplied voltage, the tilt angle is preferably 85 to 90°. In order tohave the liquid crystal composition aligned in such a manner, alignmentfilms composed of polyimide (PI), polyamide, chalcone, cinnamate,cinnamoyl, or the like may be provided. The alignment films arepreferably formed by using an optical alignment technology. A liquidcrystal composition of the present invention containing a compoundrepresented by general formula (LC0) having a partial structure in whichX⁰¹ represents F can be easily aligned along the easy axis of thealignment films and the desired tilt angle can be easily formed.

A liquid crystal composition of the present invention containing acompound represented by general formula (PC) as the polymerizablecompound can be used to form a polymer-stabilized TN-mode, OCB-mode,ECB-mode, IPS-mode, or VA-IPS mode liquid crystal display deviceprepared by polymerizing the polymerizable compounds in the liquidcrystal composition in the presence or absence of applied voltage.

EXAMPLES

The present invention will now be described in further detail by usingExamples which do not limit the scope of the present invention. Notethat the “%” for compositions of Examples and Comparative Examples belowmeans “% by mass”.

The physical properties of the liquid crystal composition are presentedas follows:

T_(N-I): nematic phase-isotropic liquid phase transition temperature (°C.)T-n: lower limit temperature (° C.) of nematic phase∈⊥: dielectric constant in a direction perpendicular to the molecularlong axis at 25° C.Δ∈: dielectric anisotropy at 25° C.no: refractive index for ordinary rays at 25° C.Δn: refractive index anisotropy at 25° C.Vth: voltage (V) applied to a 6 μm-thick cell at which the transmittancechanges by 10% when square waves are applied at a frequency of 1 KHz at25° C.Viscosity: bulk viscosity (mPa·s) at 20° C.γ₁: rotational viscosity (mPa·s)

Compounds are abbreviated as follows:

TABLE 1 n (numeral) at terminus C_(n)H_(2n+1)— -2- —CH₂CH₂— -1O- —CH₂O—-O1- —OCH₂— —V— —CO— —VO— —COO— —CFFO— —CF₂O— —F —F —Cl —Cl —CN —C≡N—OCFFF —OCF₃ —CFFF 0 —OCFF —OCHF₂ —On —OC_(n)H_(2n+1) -T- —C≡C— ndm-C_(n)H_(2n+1)—HC═CH—(CH₂)_(m−1)— -ndm —(CH₂)_(n−1)—HC═CH—C_(m)H_(2m+1)ndmO— C_(n)H_(2n+1)—HC═CH—(CH₂)_(m−1)—O— —Ondm—O—(CH₂)_(n−1)—HC═CH—C_(m)H_(2m+1)

Example 1

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 2 1d1-Cy-Cy-3 15.0% od1-Cy-Cy-1d1 15.0 2-Cy-Cy-Ph-1 5.03-Cy-Cy-Ph-1 7.0 1-Ph—Ph1—Ph-3d0 8.0 3-Cy-Cy-Ph3—OCFFF 10.03-Cy-Cy-CFFO—Ph3—F 5.0 3-Cy-Ph1—Ph3—CFFO—Ph3—F 10.0 3-Pr—Ph3—O1—Ph—OCFFF15.0 3-Pr—Ph3—O1—Ph3—F 10.0 Tni 72.2 T-n −33.0 Vth 1.42 γ1 67.0 ε⊥ 3.57Δε 8.37 no 1.486 Δn 0.094 Viscosity 13.1

Comparative Example 1

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 3 1d1-Cy-Cy-3 15.0% od1-Cy-Cy-1d1 15.0 2-Cy-Cy-Ph-1 5.03-Cy-Cy-Ph-1 7.0 1-Ph—Ph1—Ph-3d0 8.0 3-Cy-Cy-Ph3—OCFFF 10.03-Cy-Cy-CFFO—Ph3—F 5.0 3-Cy-Ph1—Ph3—CFFO—Ph3—F 10.0 3-Pr—Ph3-1O—Ph—OCFFF15.0 3-Pr—Ph—O1—Ph3—F 10.0 Tni 67.0 T-n −33.0 Vth 1.50 γ1 94.0 ε⊥ 3.55Δε 7.87 no 1.485 Δn 0.093 Viscosity 20.5

This liquid crystal composition does not contain a compound representedby general formula (LC0) having a -Ph3-OCH₂— partial structure disclosedin this application. Although Example 1 has a larger dielectricanisotropy (Δ∈) and a high nematic phase-isotropic liquid phasetransition temperature (T_(ni)), Example 1 has viscosity substantiallylower than that of Comparative Example 1, and small γ₁. This shows thatthe combination of the present invention has outstanding benefits.

Example 2

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 4 1d1-Cy-Cy-3 10.0% od1-Cy-Cy-1d1 10.0 3-Cy-Cy-2 5.03-Pr—Ph3—O1—Ph—OCFFF 5.0 3-Pr—Ph3—O1—Ph3—F 5.0 3-Pr—Ph1—Ph3—O1—Ph3—F10.0 3-Pr-Cy-Ph3—O1—Ph—OCFFF 5.0 3-Cy-Pr—Ph3—O1—Ph3—F 5.03-Cy-Cy-Ph3—O1—Ph3—F 5.0 3-Cy-Ph—Ph3—O1—Ph3—F 5.0 3-Ph—Ph1—Ph3—O1—Ph3—F10.0 3-Ph—Ph1—Np3—F 5.0 Tni 79.2 T-n −36.0 Vth 1.38 γ1 76.0 ε⊥ 3.86 Δε9.87 no 1.485 Δn 0.090 Viscosity 14.1

Example 3

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 5 0d1-Cy-Cy-3 10.0% 1d1-Cy-Cy-2 10.0 1d1-Cy-Cy-3 15.0 2-Cy-Cy-Ph-12.0 3-Cy-Cy-Ph-1 3.0 3-Pr-Cy-Ph3—O1—Ph—OCFFF 5.0 3-Cy-Pr—Ph3—O1—Ph3—F5.0 3-Cy-Ph3—O1—Ph—OCFFF 10.0 3-Ph—Ph3—O1—Ph—OCFFF 10.03-Cy-Cy-Ph3—O1—Ph3—F 10.0 3-Cy-Ph—Ph3—O1—Ph3—F 10.03-Ph—Ph1—Ph3—O1—Ph3—F 10.0 Tni 84.6 T-n −31.0 Vth 1.43 γ1 72.0 ε⊥ 3.71Δε 8.41 no 1.488 Δn 0.095 Viscosity 12.8

Example 4

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 6 1d1-Cy-Cy-2 10.0% 1d1-Cy-Cy-3 15.0 od1-Cy-Cy-1d1 15.0 3-Cy-Cy-22.0 2-Cy-Cy-Ph-1 3.0 3-Cy-Cy-Ph-1 5.0 1-Ph—Ph1—Ph-3d0 5.03-Cy-Ph—Ph3—OCFFF 5.0 3-Pr—Ph3—O1—Ph—OCFFF 5.0 3-Pr—Ph1—Ph3—O1—Ph3—F10.0 3-Cy-Ph3—O1—Ph—OCFFF 10.0 3-Ph—Ph3—O1—Ph—OCFFF 5.03-Cy-Cy-Ph3—O1—Ph3—F 10.0 Tni 76.0 T-n −39.0 Vth 1.69 γ1 60.0 ε⊥ 3.39 Δε6.40 no 1.486 Δn 0.090 Viscosity 10.7

Example 5

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 7 Compound Example 5 0d1-Cy-Cy-3 10.0% 1d1-Cy-Cy-2 15.01d1-Cy-Cy-3 15.0 od1-Cy-Cy-1d1 5.0 3-Cy-Cy-Ph3—OCFFF 5.03-Cy-Ph—Ph3—OCFFF 5.0 3-Cy-Cy-CFFO—Ph3—F 5.0 3-Cy-Ph1—Ph3—CFFO—Ph3—F 5.03-Pr—Ph1—Ph3—O1—Ph3—F 5.0 3-Pr-Cy-Ph3—O1—Ph—OCFFF 5.03-Cy-Pr—Ph3—O1—Ph3—F 5.0 3-Cy-Ph3—O1—Ph—OCFFF 5.0 3-Ph—Ph3—O1—Ph—OCFFF5.0 3-Cy-Cy-Ph3—O1—Ph3—F 5.0 3-Cy-Ph—Ph3—O1—Ph3—F 5.0 Tni 78.9 T-n −36.0Vth 1.44 γ1 74.0 ε⊥ 3.56 Δε 8.22 no 1.484 Δn 0.081 Viscosity 13.1

Example 6

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 8 0d1-Cy-Cy-3 10.0% 1d1-Cy-Cy-2 10.0 1d1-Cy-Cy-3 10.0od1-Cy-Cy-1d1 10.0 3-Cy-Cy-Ph-1 7.0 1-Ph—Ph1—Ph-3d0 8.03-Pr—Ph1—Ph3—O1—Ph3—F 10.0 3-Pr-Cy-Ph3—O1—Ph—OCFFF 10.03-Ph—Ph3—O1—Ph—OCFFF 10.0 3-Cy-Ph—Ph3—O1—Ph3—F 5.0 3-Ph—Ph1—Ph3—O1—Ph3—F10.0 Tni 91.8 T-n −36.0 Vth 1.53 γ1 79.0 ε⊥ 3.54 Δε 7.52 no 1.490 Δn0.110 Viscosity 14.3

Example 7

A vertical alignment film was formed on a first substrate that had apair of comb-shaped transparent electrodes. Another vertical alignmentfilm was formed on a second substrate that had no electrode structure.The first substrate and the second substrate were formed into an IPSempty cell having a gap spacing of 4.0 μm. The liquid crystalcomposition of Example 1 was poured into the empty cell to prepare aliquid crystal display device.

To 99% of the liquid crystal composition of Example 1, 1% of apolymerizable compound represented by formula (PC-1)-3-1 was added andhomogeneously dissolved:

As a result, a polymerizable liquid crystal composition CLC-A wasobtained. The physical properties of CLC-A were substantially the sameas physical properties of the liquid crystal composition of Example 1.CLC-A was held in the IPS empty cell described above. The liquid crystalcell was then irradiated with ultraviolet light using a high-pressuremercury lamp through a filter that cuts off ultraviolet rays of 300 nmor less while applying 1.8 V square waves at a frequency of 1 KHz. Theirradiation was conducted for 600 seconds while adjusting theirradiation intensity at the cell surface to be 20 mW/cm². As a result,a vertical-alignment liquid crystal display device in which apolymerizable compound in the polymerizable liquid crystal compositionwas polymerized was obtained. This display device had significantly highresponse speed compared to the liquid crystal display device formed byusing only the liquid crystal composition of Example 1.

1-20. (canceled)
 21. A liquid crystal composition having a positivedielectric anisotropy and containing one or more compounds selected fromcompounds represented by general formula (LC0) and one or more compoundsselected from a group of compounds represented by general formula (LC1)to general formula (LC5), wherein the liquid crystal compositioncontains one or more compounds in which at least one of A⁰¹ and A⁰² ingeneral formula (LC0) represents a tetrahydropyran-2,5-diyl group:

(In the formulae, R⁰¹ to R⁴¹ each independently represent an alkyl grouphaving 1 to 15 carbon atoms where one or more —CH₂— in the alkyl groupmay each be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C≡C—,—CF₂O—, or —OCF₂— so long as oxygen atoms are not directly adjacent toeach other and one or more hydrogen atoms in the alkyl group may each besubstituted with a halogen; R⁵¹ and R⁵² each independently represent analkyl group having 1 to 15 carbon atoms where one or more —CH₂— in thealkyl group may each be substituted with —O—, —CH═CH—, —CO—, —OCO—,—COO—, or —C≡C— so long as oxygen atoms are not directly adjacent toeach other, and may each represent —OCF₃ or —CF₃— when A⁵¹ or A⁵³described below represents a cyclohexane ring; A⁰¹ to A⁴² eachindependently represent any one of structures below:

(In the structures, one or more —CH₂— in the cyclohexane ring may eachbe substituted with —O— so long as oxygen atoms are not directlyadjacent to each other; in the structures, one or more —CH═ in thebenzene ring may each be substituted with —N═ so long as nitrogen atomsare not directly adjacent to each other; and X⁶¹ and X⁶² eachindependently represent —H, —Cl, —F, —CF₃, or —OCF₃); A⁵¹ to A⁵³ eachindependently represent any one of structures below:

(In the formulae, one or more —CH₂CH₂— in the cyclohexane ring may eachbe substituted with —CH═CH—, —CF₂O—, or —OCF₂— and one or more —CH═ inthe benzene ring may each be substituted with —N═ so long as nitrogenatoms are not directly adjacent to each other); X⁰¹ represents ahydrogen atom or a fluorine atom; X¹¹ to X⁴³ each independentlyrepresent —H, —Cl, —F, —CF₃, or —OCF₃; Y⁰¹ to Y⁴¹ each represent —Cl,—F, —OCHF₂, —CF₃, or —OCF₃; Z⁰¹ and Z⁰² each independently represent asingle bond, —CH═CH—, —C≡C—, —CH₂CH₂—, —(CH₂)₄—, —OCF₂—, or —CF₂O—; Z³¹to Z⁴² each independently represent a single bond, —CH═CH—, —C≡C—,—CH₂CH₂—, —(CH₂)₄—, —OCF₂—, or —CF₂O— where at least one of Z³¹ and Z³²that are present represents a group other than a single bond; Z⁵¹ andZ⁵² each independently represent a single bond, —CH═CH—, —C≡C—,—CH₂CH₂—, —(CH₂)₄—, —OCH₂—, —CH₂O—, —OCF₂— or —CF₂O—; m⁰¹ to m⁵¹ eachindependently represent an integer of 0 to 3; m⁰¹+m⁰², m³¹+m³², m⁴¹+m⁴²are each independently 1, 2, 3, or 4; and when a plurality of A⁰¹, A⁰³,A²³, A³¹, A³², A⁴¹, A⁴², A⁵², Z⁰¹, Z⁰², Z³¹, Z³², Z⁴¹, Z⁴² and/or Z⁵²are present, they may be the same or different).
 22. The liquid crystalcomposition according to claim 21, wherein X⁰¹ in general formula (LC0)represents F.
 23. The liquid crystal composition according to claim 21,wherein the liquid crystal composition contains one or more compoundsselected from the group consisting of compounds represented by generalformula (LC2-1) to general formula (LC2-14) as the compound representedby general formula (LC2):

(In the formulae, X²³, X²⁴, X²⁵, and X²⁶ each independently represent ahydrogen atom, Cl, F, CF₃, or OCF₃, and X²², R²¹, and Y²¹ are the sameas those in claim 21.)
 24. The liquid crystal composition according toclaim 21, wherein the liquid crystal composition contains one or morecompounds selected from the group consisting of compounds represented bygeneral formula (LC3-1) to general formula (LC3-32) as the compoundrepresented by general formula (LC3):

(In the formulae, X³³, X³⁴, X³⁵, X³⁶, X³⁷, and X³⁸ each independentlyrepresent H, Cl, F, CF₃, or OCF₃, and X³², R³¹, A³¹, Y³¹, and Z³¹ arethe same as those in claim 21.)
 25. The liquid crystal compositionaccording to claim 21, wherein the liquid crystal composition containsone or more compounds selected from the group consisting of compoundsrepresented by general formula (LC4-1) to general formula (LC4-23) asthe compound represented by general formula (LC4):

(In the formulae, X⁴⁴, X⁴⁵, X⁴⁶, and X⁴⁷ each independently represent H,Cl, F, CF₃, or OCF₃, and X⁴², X⁴³, R⁴¹, and Y⁴¹ are the same as those inclaim 21.)
 26. The liquid crystal composition according to claim 21,wherein the liquid crystal composition contains one or more compoundsselected from the group consisting of compounds represented by generalformula (LC5-1) to general formula (LC5-26) as the compound representedby general formula (LC5):

(In the formulae, R⁵¹ and R⁵² are the same as those in claim 21.) 27.The liquid crystal composition according to claim 21, wherein the liquidcrystal composition contains 5 to 50% by mass of one or more compoundsin which at least one of A⁰¹ and A⁰² in general formula (LC0) representsa tetrahydropyran-2,5-diyl group.
 28. The liquid crystal compositionaccording to claim 21, wherein the liquid crystal composition containsone or more optically active compounds.
 29. The liquid crystalcomposition according to claim 21, wherein the liquid crystalcomposition contains one or more compounds in which at least one of Z⁰¹,Z⁰², Z³¹ to Z⁴², Z⁵¹, and Z⁵² in general formula (LC0) and generalformula (LC3) to general formula (LC5) represents —CF₂O— or —OCF₂—. 30.The liquid crystal composition according to claim 21, wherein the liquidcrystal composition contains 30 to 70% by mass of the compoundrepresented by general formula (LC5) and has a viscosity η of 20 mPa·sor less at 20° C.
 31. The liquid crystal composition according to claim21, wherein the liquid crystal composition contains one or morepolymerizable compounds.
 32. The liquid crystal composition according toclaim 21, wherein the liquid crystal composition contains one or moreantioxidants.
 33. The liquid crystal composition according to claim 21,wherein the liquid crystal composition contains one or more UVabsorbers.
 34. A liquid crystal display device using the liquid crystalcomposition according to claim
 21. 35. An active matrix driving liquidcrystal display device using the liquid crystal composition according toclaim
 21. 36. A TN-mode, OCB-mode, ECB-mode, IPS-mode, or VA-IPS-modeliquid crystal display device using the liquid crystal compositionaccording to claim
 21. 37. A polymer-stabilized TN-mode, OCB-mode,ECB-mode, IPS-mode, or VA-IPS-mode liquid crystal display device thatuses the liquid crystal composition according to claim 31 and isproduced by polymerizing the polymerizable compounds in the liquidcrystal composition in the absence or presence of applied voltage. 38.The liquid crystal display device according to claim 34, wherein analignment layer that has a surface that comes into contact with liquidcrystal molecules and causes the liquid crystal molecules to alignhorizontally, tilt, or align vertically includes an alignment filmcontaining at least one compound selected from polyimide (PI),polyamide, chalcone, cinnamate, and cinnamoyl.
 39. The liquid crystaldisplay device according to claim 38, wherein the alignment layeraccording to claim 38 further includes a polymerizable liquid crystalcompound or a polymerizable non-liquid crystal compound.
 40. The liquidcrystal display device according to claim 38, wherein an alignment filmprepared by an optical alignment technology is formed as the alignmentlayer at the surface that comes into contact with the liquid crystalcomposition.